A polishing apparatus 100 includes a first electric motor 14 that rotationally drives a polishing table 12, and a second electric motor 22 that rotationally drives a top ring 20 that holds a semiconductor wafer 18. The polishing apparatus 100 includes: a current detection portion 24; an accumulation portion 110 that accumulates, for a prescribed interval, current values of three phases that are detected by the current detection portion 24; a difference portion 112 that determines a difference between a detected current value in an interval that is different to the prescribed interval and the accumulated current value; and an endpoint detection portion 29 that detects a polishing endpoint that indicates the end of polishing of the surface of the semiconductor wafer 18, based on a change in the difference that the difference portion 112 outputs.

A polishing method which can acquire an actual position of a film-thickness measurement point, and can therefore apply an optimum polishing pressure to a substrate such as a wafer is disclosed. The method includes: causing a substrate detection sensor to generate substrate detection signals in a preset cycle and causing a film-thickness sensor to generate a film-thickness signal at a predetermined measurement point during polishing of the substrate while the substrate detection sensor and the film-thickness sensor are moving across the surface of the substrate; calculating an angle of eccentricity of a center of the substrate relative to a center of the polishing head from the number of substrate detection signals; correcting a position of the predetermined measurement point based on the angle of eccentricity; and controlling polishing pressure at which the polishing head presses the substrate based on the film-thickness signal and the corrected position of the predetermined measurement point.

A polishing method which can acquire an actual position of a film-thickness measurement point, and can therefore apply an optimum polishing pressure to a substrate such as a wafer is disclosed. The method includes: causing a substrate detection sensor to generate substrate detection signals in a preset cycle and causing a film-thickness sensor to generate a film-thickness signal at a predetermined measurement point during polishing of the substrate while the substrate detection sensor and the film-thickness sensor are moving across the surface of the substrate; calculating an angle of eccentricity of a center of the substrate relative to a center of the polishing head from the number of substrate detection signals; correcting a position of the predetermined measurement point based on the angle of eccentricity; and controlling polishing pressure at which the polishing head presses the substrate based on the film-thickness signal and the corrected position of the predetermined measurement point.

A polishing apparatus includes a holder holding a target. A polisher polishes the target. An irradiator irradiates the target with an irradiation light from below the polisher. A photoreceiver receives a reflection light reflected from the polishing target to detect a relation between a wavelength and a light quantity of the reflection light. A first reflector bends the irradiation light from the irradiator in a direction tilted to the polishing target. A second reflector bends the reflection light from the polishing target to the photoreceiver. The first reflector irradiates the polishing target with the irradiation light in a direction tilted to the polishing target.

A polishing apparatus includes a holder holding a target. A polisher polishes the target. An irradiator irradiates the target with an irradiation light from below the polisher. A photoreceiver receives a reflection light reflected from the polishing target to detect a relation between a wavelength and a light quantity of the reflection light. A first reflector bends the irradiation light from the irradiator in a direction tilted to the polishing target. A second reflector bends the reflection light from the polishing target to the photoreceiver. The first reflector irradiates the polishing target with the irradiation light in a direction tilted to the polishing target.

A polishing pad for CMP is provided. The polishing pad includes a layer of material having a surface, a plurality of grooves indented into the surface in the layer of material, and a fluorescent indicator in the layer of material. Each of the plurality of grooves has a first depth, the fluorescent indicator has a second depth, and the second depth is equal to or less than the first depth.

A polishing pad for CMP is provided. The polishing pad includes a layer of material having a surface, a plurality of grooves indented into the surface in the layer of material, and a fluorescent indicator in the layer of material. Each of the plurality of grooves has a first depth, the fluorescent indicator has a second depth, and the second depth is equal to or less than the first depth.

A method of controlling polishing includes storing a base spectrum, the base spectrum being a spectrum of light reflected from a substrate after deposition of a deposited dielectric layers overlying a metallic layer or semiconductor wafer and before deposition of a non-metallic layer over the plurality of deposited dielectric layer. After deposition of the non-metallic layer and during polishing of the non-metallic layer on the substrate, measurements of a sequence of raw spectra of light reflected the substrate during polishing are received from an in-situ optical monitoring system. Each raw spectrum is normalized to generate a sequence of normalized spectra using the raw spectrum and the base spectrum. At least one of a polishing endpoint or an adjustment for a polishing rate is determined based on at least one normalized predetermined spectrum from the sequence of normalized spectra.

A wafer thinning system and method are disclosed that includes grinding away substrate material from a backside of a semiconductor device. A current change is detected in a grinding device responsive to exposure of a first set of device structures through the substrate material, where the grinding is stopped in response to the detected current change. Polishing repairs the surface and continues to remove an additional amount of the substrate material. Exposure of one or more additional sets of device structures through the substrate material is monitored to determine the additional amount of substrate material to remove, where the additional sets of device structures are located in the semiconductor device at a known depth different than the first set.

A wafer thinning system and method are disclosed that includes grinding away substrate material from a backside of a semiconductor device. A current change is detected in a grinding device responsive to exposure of a first set of device structures through the substrate material, where the grinding is stopped in response to the detected current change. Polishing repairs the surface and continues to remove an additional amount of the substrate material. Exposure of one or more additional sets of device structures through the substrate material is monitored to determine the additional amount of substrate material to remove, where the additional sets of device structures are located in the semiconductor device at a known depth different than the first set.